Information codes such as bar codes and two-dimensional codes have been printed on sticky labels and attached to components and the packages of products for production management and distribution management thereof (refer to Patent literature 1).
General methods for writing such information codes on sticky labels include a laser marking method and an ink marking method. In the ink marking method, ink having a lightness different from that of a base material is applied to a surface to write the code thereon. In the laser marking method, a surface of a sticky label is illuminated by a laser to form indentations on the surface to write the code thereon (refer to Patent literature 2).
Retroreflective materials have been used as materials for showing traffic signs, such as directional signs and regulatory signs, for traffic-accident preventive measures, and in clothing for night workers at roadworks, police officers, and fire fighters. Retroreflective materials have also been used for clothing, shoes, and bags for the same purpose while jogging and walking at night, and have been used recently for the purpose of enhancing fashionability. Since it is difficult to imitate retroreflective materials when special materials are used or when the material composition and manufacturing processes are strictly controlled, retroreflective materials are affixed to genuine articles in many cases to distinguish them from forgeries or imitations (refer to Patent literature 3).
Products have also been proposed that combine retroreflective materials, which have a high forgery prevention effect as described above, and information codes to achieve both the distinction between genuine articles and forgeries or imitations (improvement in security) and article information management with the use of the information codes (refer to Patent literature 4).    Patent literature 1: Japanese Unexamined Patent Application Publication No. 2002-19253    Patent literature 2: Japanese Patent No. 2719287    Patent literature 3: Japanese Unexamined Patent Application Publication No. 2000-272300    Patent literature 4: Japanese Unexamined Patent Application Publication No. 2004-268258